Card feed station



Sept; 17, 1957 K. R. CARLISLE CARD FEED STATION Filed Mrcn 1, 1955` EZ@-3. l

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CARD FEED STATGN Kenneth Robert Cariisle, rfoi-rance, Calif., assignerto Hnghes Aircraft Company, Culver City, Saixf., a corporation ofDelaware Application March 1, 1955, Serial No. 491,372

1 Claim. (Cl. 271-11) This invention relates to devices for feedingcards to a conveyor, and more particularly to a device for feedingpunched cards or the like at a rapid rate to a fast-moving conveyor.

It is well known in the prior art to employ conveyors for processingdocuments, photographs, or cards in a continuous process. Such conveyorsmay utilize gravity, friction, or vacuum either for picking up astationary card; or for retaining a moving card upon the conveyor.

The present invention relates specifically to a feed station for feedingcards to a high-speed conveyor of the type which employs a frictionpickup. It is necessary in utilizing the present invention, in order topick up and move one cardat a time from a stack of cards, that thecoeicient of kinetic friction between a card to be moved and the surfaceor" the conveyor shall be greater than the coefficient of staticfriction between two of such cards.

In 'the prior art it is well known to employ a card feed station whichutilizes moving mechanical parts for releasing each card individually,one at a time. Such devices provide very satisfactory operation, buttheir maximum operating rate is limited to a few hundred cards perminute. v

The invention is illustrated in conjunction with a system wherein anumber of punched cards of the type used with business data processingequipment are to be transported from one location to another in acontinuousprocess. A stack of cards to be processed is arrangedhorizontally in an input magazine from whence they are picked up by afirst rotating drum, passed on to a second rotating drum, and thenreceived in a horizontally arranged output magazine. The rst or pickupdrum rotates at a high rate of speed about a vertical axis, and picks upthe cards from the input magazine primarily through friction, but withpartial assistance from a vacuum maintained within the drum. T hesurface of the drum is perforated with holes or slots in order that thevacuum may produce a lower air pressure on the side of the card which isadjacent to the surface of the drum.

It is, therefore, an object of the invention to provide a device forfeeding cards at a rapid rate to a rapidly moving conveyor.

Another object of the invention is to provide a device, having no movingparts, for feeding cards to a conveyor of the friction type which may bea rotating vacuum drum for retaining a card that has been picked up.

A further object of the invention is to provide a device for feeding ata rapid rate, a stack of cards which is arranged horizontally in aninput magazine to the surface of a drum which is rotating rapidly abouta vertical axis and which accomplishes the pickup of the cards primarilyby friction and secondarily by means of a partial vacuum within thedrum.

ri'he novel features which are believed to be characteristic of theinvention, both as to its organization and vmethod of operation,together with further objects and advantages thereof, will be betterunderstood from the 2,806,695 ?atented Sept. 17, 1957 followingdescription considered in connection with the accompanying drawing inwhich an embodiment of the invention is illustrated by way of example.It is to be expressly understood, however, that the drawing is for thepurpose of illustration and description only, and is not intended as adefinition of the limits of the invention.

Fig. 1 illustrates in schematic form a card transfer system wherein thecard feed station of the present invention may be utilized;

Fig. 2 is an enlarged plan view of a card feed station in accordancewith the present invention; and A Fig. 3 is a vertical cross sectionview of the card feed station taken on line 3 3 of Fig. 2.

Reference is now made to Fig. l wherein a card transfer system isillustrated in schematic form. An input magazine lil contains a stack ofcards 11 which are kept in place by means of a pressure device indicatedschematically by an arrow 12. A vacuum pickup drum 13 rotating in thedirection indicated by the arrow is arranged to pick up the cards fromthe input magazine and to send them through a chute 14 to a reversingdrum 15 which rotates in an opposite direction shown by the arrow. Avacuum pump 16 is utilized for maintaining a partial vacuum in each ofthe drums, and each drum surface has perforations or slots for holdingthe cards on the drum surface. An output magazine 17 is shown containinga stack of cards i3 which has already been transferred, the stack beingmaintained in position by another pressure device indicated by an arrow19.

in the system of Fig. l the card feed station is indicated generally bymeans of an arrow 20, and a card stacking station adjacent to the outputmagazine is indicated generally by an arrow 21. For the purpose of thepresent invention, it is necessary to describe only the card feedstation in greater detail, hence reference is made to Fig. 2 for thatpurpose.

In Fig. 2 there is shown an enlarged and plan view of the card feedstation of the system of Fig. l. The pickup drum is again designated bythe numeral i3 and the input magazine by the numeral iti. The stack ofcards is designated generaly by the numeral 11, and the cards of thestack adjacent the drum are specifically identified by referencecharacters lia, 11b, 11e, and lid. The input magazine i@ is shown asincluding a lower retaining wall 30, a stationary end piece 3l, and anupper retaining wall 32. Between the end piece 3i and the upperretaining wall 32 there is provided an aperture through which the firstcard of the stack may be picked up by the revolving drum i3.

That portion of retaining wall 32 which is in nearest proximity to therevolving drum 13 will be referred to as the feed throat. Significantfeatures of the feed throat include a curved guiding surface 33, a lirstvertex 34, and a second vertex 35. Vertex 34 is spaced from the surfaceof the drum by a distance which is equal to the thickness of from 2 to 5cards. Vertex 35 is spaced from the surface of the drum by a distancewhich is more than the thickness of one card, but less than thethickness of two cards.

In operation, the revolving drum picks up the rst card such as lla bymeans of friction, and carries it around during the rotation of thedrum, a clamping or holding action being obtained because of the partialvacuum the drum. The vacuum conveyor principle is well known and needsno further explanation here; for example, U. S. Patent No. 1,968,941,issued on August 7, 1934, to B. I. Hall et al., shows a series ofevacuated drums used for transporting a set of papers from one positionto another while various operations are performed thereon. In order forthe card ila to be picked up by the surface of the drum, however, it isnecessary that the coefficient of kinetic friction between the card andthe drum should be greater than the coecient of static friction betweenthe card 11a and the adjacent card 11b. It has been found that aluminumor steel provides a satisfactory surface for the drum. AIt is o f coursenecessary to keep the cards clean and `dry ill. order toprevent them`from sticking to each other.

The function of curved surface 33 is to permit the cards to startseparating fromreach other before they reach the surface of the d mm.YThus as card 11a is pulled out of the input magazine by the rotatingaction of the drum, it in turn slides card 11b toward the top of Fig. 2,card 11b in turn'slides card 11C, and so forth. Curved surface 33therefore permits the cards to be gradually channeled toward theirdestination, and at the same time permits any static friction bond whichmay exist between two adjacent cards to be broken before the actual feedpoint` ist. reached. c

'The function of -vertex 34 is to limit the number of cards which may bepulled from the magazine atl one time. Thus, depending upon theparticular dimension which is chosen, between two and five cards at onetime may be permitted to slide past vertex 34. The function of vertex 35is to permit only one card at a time to pass between itself and thedrum.

From actual operating experience, it has been found that even though thedistance between the vertex 34 and thel drum may be adjusted to permitas many as live cards to pass through, lin most cases only a single cardwill actually pass. The phenomenon appears to be somewhat statistical innature, with two cards at a time being passed beyond the vertex 34 aboutone time in 50. Vertex 35, on the other hand, whether it is presentedwith one or more cards, will permit only a single card to pass throughat one time. Thus a very smooth, even feeding action is achieved,

Although the input magazine has been illustrated in Fig. 2 as includinga lower retaining wall 30 and an end piece 31, actual operatingexperience has shown that these parts of the structure are unnecessary.In lieu, thereof, it is deemed preferable to employ a drum shieldcovering the surface of the drum for protecting the Vacuum therein, thedrum shield being arranged so that it effectively replaces the end piece31, a substantial aperture being provided between the drum shield andthe vertex 35 so as to expose the cards to the pick-up drum.

The placement of the parts with respect to each other needs also to Ibedescribed. The inner surface of end piece 31 is aligned in a straightline with vertex 35. Vertex 35 is placed a small distance off centerwith respect to the drum. Thus a dotted line 37 represents the drumradius drawn in a direction which is parallel to the direction of cardfeed. It will be noted from Fig. 2 that vertex 35 is located somewhatabove radius 37. In a specific embodiment of the invention, where verysatisfactory results were obtained, a drum diameter of l Vinches wereused, and vertex 34 was situated a half inch above line 37. Otherspecific information may conveniently be given in tabular form asfollows:

Drum diameter, l0 inches Card size (IBM cards), 7% inches long, 3%inches wide, 7 mils thick Length of aperture between wall 31 and vertex35,` 21/1 inches Radius of curved surface 33, 1.83 inches Distance ofvertex 35 from drum surface, 8 mils Distance of vertex 34 from drumsurface, 20 milsV Olfset-of vertex 34 from lower surface of Wall 32, 380

mils

Vertical offset of vertex 35 from vertex 34, 244 mils Distance of vertex34 above drum radius 37, 1/2 inch 'Y Additional descriptionv ofoperation will now be given Withreferenceto Fig. 2. The stack of cardsis pushed forward by' means of the pressure device 12. The cards whcharenearest to the surface of theV drum become separated from each other bymeans of the curved surface 33, as previously indicated. The sidewisemovement of one or more cards past the vertex 34, in response tofrictional thrust from the drum, provides additional separation. It istherefore evident that card 11a, which is ready to be picked up by thedrum, is separated from the next card 11b by a denite amount of space.This pery mits the vacuum within the drum to become an aiding factor inpicking up the card, since normal atmospheric pressure i5 applied to theback side of the card, whereas the front side faces against the vacuumat the surface of the drum.

In the operation of the card feed station of Fig. 2, an important pointis the matter as to when each card is picked up. It is not permissibleto have two cards picked up at once as this would result in the loss ofthe second card by falling from the drum during the revolution of thedrum. As previously pointed out, the vertex permits only a single cardto pass thereunder at any given time. Thus, when one card has passedunder the vertex 35, it becomes possible for the next succeeding card tomake contact with the drum.

It will'be noted that in the particolar example shown in Fig. 2 there isa substantial aperture between end piece 3l and vertex 35 (orl between adrum shield and vertex 35) and the length of the aperture may be 21/2inches. It is therefore possible for the second card 11b to make contactwith the drum surface before the first card 11a has passed entirelythrough the feed throat; for example, the second card may come incontact with the drum surface when ahalf inch of the'rst card yetremains to pass through vertex 35. The ultimate spacing between thefirst and second cards, however, is determined not by the time when thesecond card 11b first contacts the drum surface, but rather by theamount of time required to accelerate the second card up to theY drumspeed. In actual practice it has been found that the time delay, orslippage, which occurs while the second card is being accelerated todrum speed is adequate to reliably provide a space -between successivemoving cards. It has been found that the space between cards is randomand varies from 1A in 2 inches. From the foregoing discussion, it isevident that the card feed rate may be conveniently adjusted by asuitable adjustment of the rotational velocity of the pick up drum,

Reference is now made to Fig. 3 wherein the card feed station of Fig. 2Vis shown in vertical cross section, with like parts being identified bylike numeralsf A suitable horizontal supporting mechanism for the inputmagazine is designated by numeral 38. It will be noted that the heightof the input magazine as shown byV side walls 30 and 32 and the endpiece 31 is somewhat less than the width of the cards. This relationshipis not critical, and satisfactory operation has been obtained with afeed throat having vertexes 34 and 35, each of which extended less thanhalf the width of the cards. On the other hand, equally satisfactoryoperation may be obtained where the vertexes 34 and 35 Vare ahnost equalto the card width, as shown. With speciiic values as shown above,satisfactory operation of the card feed station has beenrobtained atcard rates as high as 4,000 per minute, The system requires no movingparts other than the drum, and it is relatively easy to adjust the drumfor theone critical dimension, namely, Vthe spacing of vertex 35 must besufficient to permit one card to pass, but not suicient to permit twocards to pass. n

It is therefore apparent that the present invention providesa novel cardfeed station which, without the use of any moving parts, provides asmooth, even card feed at a rapid rate to a conveyor which employsfriction pickup. Operating rates with IBM punched cards may be obtainedfrom two to four thousand cards per minute. Y

What is claimed as new is: Y

An automatic system forV continuously movingiflexible punched cards froma card stackk at a rate in excess of one thousand cards per minute andtransporting them in a spaced sequential relation, said systetmcomprising: a cylindrical drum rotatable abcut a vertical aXis, saiddrum including a peripheral surface formed of material providing acoecient of kinetic friction between a card and said surface which isgreater than the coecient of static friction between two cards; meansfor supplying a partial vacuum to said peripheral surface duringrotation of said drum; an input magazine xedly positioned with respectto said drum for supporting the card stack and tangentially presentingone card at a time to said peripheral surface; means associated withsaid input magazine for urging the stack against said peripheralsurface; and a feed throat mounted on said input magazine and includinga rst vertex spaced with respect to said peripheral surface so as topermit at least two cards to be simultaneously transported therebetween,a second vertex laterally displaced 'om said rst Vertex in the directionof motion of said peripheral surface and spaced therefrom so as topermit only one card :at a time to be transported therebetween, and asmoothly curved convex surface contiguous to said rst verter; forproducing continuing lateral displacement of each card with respect tothe preceding and succeeding cards of the stack when the stack is movingtowards said peripheral surface, whereby when said drum is rotating eachsuccessive card of the stack is drawn out of said input magazine bymeans of kinetic frictional thrust from said peripheral surface aided bysaid partial vacuum and is thereafter retained on said peripheralsurface solely by virtue of said partial vacuum.

References Cited in the le of this patent UNITED STATES PATENTS1,515,986 `Wright Nov. 18, 1924 1,596,056 Mader Aug. 17, 1926 2,057,279Shomaker Oct. 13, 1936 2,220,073 Belcher Nov. 5, 1940

